About | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange

melodic noetic   Show EOL distros: 

API Stability

This package should be considered as stable, except for support of the Classic controller, which requires additional testing.

System Dependencies

The package depends on the third-party cwiid wiimote bluetooth interface. With permission of the author, Donnie Smith, cwiid is distributed as the ROS package cwiid.

NOTE: The cwiid library currently only recognizes Wiimotes which report the name as "Nintendo RVL-CNT-01"; the latest Wiimotes will not be discovered. See http://wiibrew.org/wiki/Wiimote#SDP_information.

Python needs to be installed on your system. This package has been tested under Python 2.5.2 and 2.6.5.

Installing the wiimote Package

Check out the wiimote package, and rosmake to ready the package for operation. Plug the Bluetooth dongle into your machine's USB port.

If you have the Motion+ Wiimote attachment, plug it into the bottom of your Wiimote device.

Make sure your Wiimote's batteries are charged.

Nodes

wiimote_node.py

wiimote_node.py publishes Wiimote sensor data and allows ROS clients to control LED and Rumble.

Subscribed Topics

set_feedback (sensor_msgs/JoyFeedbackArray)

• Topic where ROS clients control the Wiimote's leds and rumble (vibrator) facility.

Published Topics

joy (joy/Joy)

• Topic on which Wiimote accelerometer, gyro, and button data are published. Axes are: linear AccelerationX/Y/Z, followed by angular velocityX/Y/Z (a.k.a. Roll, Pitch, Yaw, a.k.a. Phi, Theta, Psi). The values are corrected to be near zero at rest. For raw values, use the State message. The Wiimote buttons are reported in the same order as in the State message (see below).

imu/data (sensor_msgs/Imu)

• Topic on which Wiimote gyro and accelerometer data are sent out.

wiimote/state (wiimote/State)

• Topic for comprehensive information about Wiimote state.

wiimote/nunchuk (joy/Joy)

• Topic on which data from an attached Nunchuk are sent out, including the joystick, accelerometer and button data. Axes are: Joystick X/Y, Acceleration X/Y/Z. The buttons are Z then C. Note the spelling of the topic name does not include a 'c'.

wiimote/classic (joy/Joy)

• Topic on which data for a Wiimote classic attachment are sent out (Untested by Willow Garage).

imu/is_calibrated (std_msgs/Bool)

• Latched topic for learning the most recent Wiimote calibration result.

Services

imu/calibrate (std_srvs/Empty)

• Service to request that the Wiimote be re-calibrated.

The State Message

The State message communicates all data that is available from your Wiimote device. Samples are taken and broadcast at 100Hz. Here are comments on some of the fields:

The message header's time stamp is set to reflect the time when the respective message's sample was taken from the Wiimote device.

The angular_velocity_zeroed shows the Motion+ gyroscope reading. These values are valid only if the Motion+ attachment is plugged into the Wiimote. Else they are held at constant zero, and matrix entry [0,0] in message field angular_velocity_covariance is set to -1.

The gyro reading is corrected by the zero-motion bias of the gyro. This bias was determined during the initial pairing/calibration process. The angular_velocity_raw is the uncorrected, raw gyro reading.

It is safe to remove the Motion+ from the Wiimote device while the wiimote node is running. However, plugging the appendage back in will not resume readings. You will need to stop and restart the Wiimote node.

The accelerometer readings are shown analogously to the gyro readings. However, the accelerometer bias is not obtained through observation during calibration, but is read from the Wiimote. The devices come with this information factory installed.

The buttons array shows which buttons are currently depressed on the Wiimtoe device. The position mapping is as follows:

Position   Button Name
0         1
1         2
2         A
3         B (toggle button on back of device)
4         Plus
5         Minus
6         Rocker Left
7         Rocker Right
8         Rocker Up
9         Rocker Down
10        HOME

LED and Rumble (vibrator) states are simple Booleans.

The ir_tracking are four sets of x/y/[z], and size measures, for the four infrared light sources that the Wiimote device can track. When no lights are detected, the respective values are set to -1. The z axis is always -1, as it is not measured.

The ir_sizes array are four intensity measures of the lights that the camera observes. The meaning of these measures are unclear to the author.

The raw_battery entry is the battery charge reading. The unit of this number is unclear. Field percent_battery returns the remaining charge as a percentage of full charge.

The zeroing_time is the time of the most recent device calibration.

The errors field is currently not used.